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Journal of Environmental sciences 2024年第4期138卷 266-276页

作者： Xu Liu Xun Wang Dingyong Wang College of Resources and Environment Southwest UniversityChongqing 400715China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury(Hg)trends,but with the large knowledge gaps in the *** this study,we comprehensively evaluated the Hg source,radial translocation and age effect of Masson pine(Pinus massoniana)tree ring at *** in chongqing,to assess the suitability of such tree ring as the archive of atmospheric *** showed that distinct variabilities among Masson pine tree-ring Hg concentration *** Hg concentration significantly increased along with stem height(P<0.05),indicating the Hg in tree rings mainly derived from foliage uptake atmospheric *** found a distinct age effect that the tree ring of young trees had the higher Hg ***,we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree *** modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in *** finally suggest that in further Hg dendrochemistry,better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.

关键词： Masson pine Tree-ring mercury Radial translocation Tree age effect

Rational design, synthesis and prospect of biodegradable magnesium alloy vascular stents

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Journal of Magnesium and Alloys 2023年第9期11卷 3012-3037页

作者： Senwei Wang Chengao Du Xin Shen Xiong Wu Sihui Ouyang Jun Tan Jia She Aitao Tang Xianhua Chen Fusheng Pan College of Materials science and Engineering Chongqing UniversityChongqingChina National Engineering Research Center for Mg Alloys Chongqing UniversityChongqingChina Beijing Amsinomed Medical Co LtdBeijingChina

Biodegradable magnesium(Mg) alloys are expected to be promising materials for cardiovascular stents(CVS), which can avoid the longterm clinical problems of current CVS, such as in-stent restenosis, late stent thrombosis, etc. Mg alloy stents exhibit superior biocompatibility and tunable biodegradability, compared with conventional permanent metallic stents. However, the poor formability and non-uniform corrosion of Mg alloy stents hinder their clinical application of CVS. This review focuses on the development of Mg alloys for CVS in recent *** to the results of bibliometric analysis, we analyzed different biodegradable Mg alloy systems. Moreover, the structural design strategies for Mg alloy stents that can reduce the stress concentration, as well as the surface modification methods to control the corrosion behavior and biological performance of Mg alloy stents are also highlighted. At last, this review systematically discussed the potential directions and challenges of biodegradable magnesium stents(BMgS) in cardiovascular fields.

关键词： Mg alloy micro-tube Biodegradable Mg stent Alloying design Structural design Functional properties

Tribocorrosion Behavior and Degradation Mechanism of 316L Stainless Steel in Alkaline Solution:Effect of Tribo-Film

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Acta Metallurgica Sinica(English Letters) 2022年第8期35卷 1365-1375页

作者： Jingyi Zou Zhongwei Wang Yanlong Ma Liwen Tan College of Material science and Engineering Chongqing University of TechnologyChongqing 400054China

Tribocorrosion behavior and degradation mechanism of 316L stainless steel(SS)in alkaline solution were *** SS was worn in 0.1 mol/L NaOH solution with different potentials to investigate the synergism between wear and *** SS showed larger material loss at a cathodic potential of-0.8 V and lower material loss at anodic potential when compared with that under pure wear *** was inverse when compared with that in other corrosive media,such as H_(2)SO_(4)and NaCl *** formation of Tribo-films with different properties at different potentials played decisive role in the degradation ***-films were formed at cathodic potential(-0.8 V)and anodic potentials(0 and 0.4 V).The tribo-film formed at-0.8 V had the highest O content and was very *** resulted in the easily peeling off of the film and then the acceleration of material *** contrast,the Tribo-films formed at anodic potentials were more complete and the O content was much *** kind of ductile Tribo-films could protect the SS from *** locally high concentration of OH-produced in the reduction reaction of oxygen at-0.8 V could react with the tribo-film which consist of nano-particles(NPs)with high chemical activity and finally led to deep oxidation and embrittlement of the *** passivation of the NPs at the anodic potentials could inhibit the oxidation of tribo-film to maintain its ductility.

关键词： Tribocorrosion 316L stainless steel NaOH Tribo-film Nano-particles

Microstructural characteristics and properties in centrifugal casting of SiC_p/Zl104 composite

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中国有色金属学会会刊：英文版 2009年第6期19卷 1410-1415页

作者：王开薛寒松邹茂华刘昌明 College of Materials science and Engineering Chongqing University Institute of Metals Research Chinese Academy of Sciences

The microstructural characteristics and Brinell hardness of a cylinder produced by centrifugal casting were investigated using 20%(volume fraction)SiCp/Zl104 *** and XRD analysis show that most of SiC particles segregate to the external circumference of the cylinder,the other SiC particles maintain in the inner circumference of the cylinder,and a free particle zone is left in the middle circumference of the *** characteristics and quantitative assessment of SiC particles show that most of congregated SiC particles in 20%SiCp/Zl104 composites are dispersed by centrifugal force,and the other congregated SiC particles and most of alumina oxide are segregated to the inner circumference of the *** SiC particles in aluminum melt can promote the refinement of primaryα(Al)during solidification,and fine primaryα(Al)grains can also promote the uniform distribution of SiC *** hardness of SiCp/Zl104 composites is connected with not only the volume fraction of SiC particles,but also the distribution of SiC particles in matrix alloy.

关键词：复合材料离心铸造铸造性能 SiC颗粒颗粒体积分数 SiC粒子 X射线衍射分析碳化硅颗粒

Circuitry implementation of a novel four-dimensional nonautonomous hyperchaotic Liu system and its experimental studies on synchronization control

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Chinese Physics B 2009年第6期18卷 2168-2175页

作者：罗小华周围李锐梁亦龙罗明伟 College of Communication and Information Engineering Chongqing University of Posts and Telecom College of Biological Information Chongqing University of Posts and Telecom College of Automation Chongqing University of Posts and Telecom

Based on the three-dimensional Liu chaotic system, this paper appends a feedback variable to construct a novel hyperchaotic Liu system. Then, a control signal is further added to construct a novel nonautonomous hyperchaotic Liu system. Through adjusting the frequency of the control signal, the chaotic property of the system can be controlled to show some different dynamic behaviors such as periodic, quasi-periodic, chaotic and hyperchaotic dynamic behaviours. By numerical simulations, the Lyapunov exponent spectrums, bifurcation diagrams and phase diagrams of the two new systems are studied, respectively. Furthermore, the synchronizing circuits of the nonautonomous hyperchaotic Liu system are designed via the synchronization control method of single variable coupling feedback. Finally, the hardware circuits are implemented, and the corresponding waves of chaos are observed by an oscillograph.

关键词： Liu chaotic system Liu hyperchaotic system nonautonomous system synchronization control

Shape- and size-dependent catalysis activities of iron-terephthalic acid metal-organic frameworks

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science China Chemistry 2015年第10期58卷 1553-1560页

作者： Yali Liu Pengfei Gao Chengzhi Huang Yuanfang Li Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University) Ministry of Education College of Chemistry and Chemical Engineering Southwest University College of Pharmaceutical science Southwest University

Precise control of the size and morphology of metal-organic frameworks(MOFs) presents an important direction for extending these inorganic-organic materials to many more advanced applications. However, because of the limit of the crystal-growth rule and mechanism, good-control of the size and morphology of MOFs remains challenging. In this contribution, an iron-terephthalic acid metal-organic framework with different shapes(octahedron, spindle and bipyramidal hexagonal) was easily and reproducibly synthesized via a solvothermal method. Sodium acetate and glycerol were used as modulators. Mechanism studies showed that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Further investigations showed that the as prepared MOFs exhibit shape-dependent catalytic activities, which means that MOFs can be designed to perform different catalytic functions. This investigation not only provides an effective guideline for the precise control of the size and morphology of metal-organic frameworks, but also extends MOFs to much more advanced applications in terms of catalyst chemistry.

关键词： controllable synthesis metal-organic frameworks catalytic activity

An optimal flow rate allocation model of the oilfield treated oil pipeline network

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Petroleum 2024年第1期10卷 93-100页

作者： Hai Li Tianyou Fan Kun Wang Xueyuan Long Yu He Meng Wang Wen Cheng Qian Huang Huirong Huang Weichao Yu PetroChina Southwest Oil&Gasfield Company Chengdu 610056China China Petroleum Planning&Engineering Institute Beijing 100083China School of Petroleum Engineering Chongqing University of Science and TechnologyChongqing 401331China PipeChina Oil&Gas Control Center Dongtucheng RoadChaoyang DistrictBeijing 100028China

Oilfield treated oil pipeline network is the link connecting the upstream oilfields and the downstream *** to the differences in operating costs and transportation fee between different pipelines and the fluctuation in the demand and sales prices of the treated oil,there is an optimal flow allocation plan for the pipeline network to make the oilfield company obtain the highest social and economic *** this study,a mixed integer nonlinear programming(MINLP)model is developed to determine the optimal flow rate allocation plan of the large-scale and complex treated oil pipeline network,and both the social and economic benefits are considered *** optimization objective is the multi-objective which includes the largest user satisfaction and the highest economic *** model constraints include the oilfield production capacity,refinery demand,pipeline transmission capacity,flow,pressure,and temperature of the node and station,and the pipeline hydraulic and thermal *** 3.7 is utilized for the programming of the off-line calculation procedure and the MINLP model,and GUROBI 9.0.2 is served as the MINLP ***,the model is applied to a real treated oil pipeline network located in China,and three optimization scenarios are *** social benefit,the values of the user satisfaction of each refinery and the total network are 1 before and after optimization for scenarios 1,2,and *** economic benefit,the annual revenue can be increased by 0.227,0.293,and 0.548 billion yuan after the optimization in scenario 1,2,and 3,respectively.

关键词： Treated oil pipeline network Flow rate allocation Optimal User satisfaction Economic benefit

Functional Characterization of a Putative Nitrate Transporter Gene Promoter from Rice

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 795-802页

作者： Ting-Zhang HU~(1,3) Kai-Ming CAO~1 Mian XIA~2 Xi-Ping WANG~(1,2*) 1 Department of Biochemistry,School of Life science Fudan University,Shanghai 200433,China 2 National Center for Molecular Crop Design,Weiming Kaituo Agriculture Biotech Co.,Ltd.,Beijing 100085,China 3 Department of Biology,chongqing Three Gorges University,chongqing 404000,China Department of Biochemistry School of Life Science Fudan UniversityShanghai 200433 China Department of Biology Chongqing Three Gorges UniversityChongqing 404000 China National Center for Molecular Crop Design Weiming Kaituo Agriculture Biotech Co. Ltd.Beijing 100085 China

Drought is one of the most significant abiotic stresses that influence plant growth *** analysis revealed that OsNRT1.3,a putative nitrate transporter gene in rice,wasinduced by *** confirm if the OsNRT1.3 promoter can respond to drought stress,a 2019 bpupstream sequence of OsNRT1.3 was *** OsNRT1.3 promoter fragments were generated by5′-deletion,and fused to the β-glucuronidase (GUS) *** chimeric genes were introduced into ***2019::GUS,NRT1196::GUS and NRT719::GUS showed similar expression patterns in seeds,roots,leaves and flowers in all transgenic rice,and GUS activity conferred by different OsNRT1.3 promoterfragments was significantly upregulated by drought stress,indicating that OsNRT1.3 promoter responds todrought stress and the 719 bp upstream sequence of OsNRT1.3 contains the drought response elements.

关键词： deletion analysis drought nitrate transporter OsNRT1.3 promoter

Influence of impurities on damping properties of ZK60 magnesium alloy

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Transactions of Nonferrous Metals Society of China 2010年第7期20卷 1305-1310页

作者：陈先华毛建军潘复生彭建王敬丰 College of Materials science and Engineering Chongqing University National Engineering Research Center for Magnesium Alloys Chongqing University

The influence of impurities on damping capacities of ZK60 magnesium alloys in the as-cast,as-extruded and T4-treated states was investigated by dynamically mechanical analyzer at room *** and Lucke dislocation pinning model was employed to explain damping properties of the *** is found that reducing impurity content can decrease the amount of second-phase particles,increase grain size and improve damping capacity of the as-cast alloy *** as-extruded alloy with lower impurity content is found to possess obviously higher damping capacity in the relatively high strain region than that with higher impurity concentration,which appears to originate mainly from different dislocation *** variation tendency of damping property with change of impurity content after solution-treatment is also similar to that in the as-extruded and as-cast states. Meanwhile,the purification of the alloy results in an evident improvement in tensile yield strength in the as-extruded state.

关键词： ZK60 magnesium alloy impurities damping dislocation

Photocatalytic and photochemical processes of AgCl/TiO_(2) studied with a fully integrated X-ray photoelectron spectrometer

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Rare Metals 2021年第4期40卷 799-807页

作者： Kai Zhou Wen-Lu He Xiao Zhang Bin Zhang Xiang-Nan Gong Kai-Wen Wang Zhi-Chao Zhang Xi-Lan Zhang Zhi-Ning Xia Xiao-Yuan Zhou Analytical and Testing Center Chongqing UniversityChongqing 401331China College of Physics Chongqing UniversityChongqing 401331China Beijing Key Laboratory and Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China School of Materials science and Engineering Chongqing UniversityChongqing 400045China

A fully integrated X-ray photoelectron spectrometer(XPS) was employed for the investigation of the separation processes and recombination behaviors of photogenerated electrons and holes on the surface of AgCl and ultra-small nano-titanium oxide cluster composite photocatalyst(AgCl/TiO_(2)).A facile route,by direct colloidal synthesis,for preparing AgCl/TiO_(2)with high stability and enhanced visible light(Vis) driven catalytic activity was *** photocatalytic activity of AgCl/TiO_(2),which revealed that the photo-degradation rate of the as-prepared AgCl/TiO_(2)was nearly 10.5 times higher than that of bare AgCl,was evaluated by applying it to the photo-degradation of methyl orange(MO) in water ***,AgCl/TiO_(2)exhibited an outstanding long-term stability during ten cycles of *** band gap of AgCl decreased from 3.25 to 2.85 eV because of the ultrasmall nano-TiO_(2)clusters that were pinned to its *** results indicate that the band gap narrowing and surface plasmon resonance(SPR) of Ag(0) were two major contributors to the enhancement of the photocatalytic activity of AgCl/TiO_(2)by improving the utilization of *** situ XPS analysis was,therefore,certified as a beneficial method to explore the catalytic mechanism of photocatalysts.

关键词： Photocatalysis AgCl/TiO_(2) Fully integrated XPS Band gap narrowing